A drill chuck is known that has a spindle extending along an axis, a chuck body fixed on the spindle and generally centered on the axis, and a tightening sleeve surrounding the body, rotatable thereon about the axis, and formed with a plurality of axially forwardly open angled guides spaced angularly about the axis. The sleeve cannot move axially relative to the body. A plurality of jaws angularly spaced about the axis are axially shiftable in the guides between a closely radially spaced and axially forward position and a widely radially spaced and axially rearward position. A pusher rotationally coupled to the jaws bears axially forward on the jaws, so that the sleeve, jaws, and pusher fit together for joint angular movement. Interengaging screwthreads couple the pusher to the chuck body so that relative rotation of the sleeve together with the jaws and pusher relative to the chuck body axially displaces the jaws between their positions. The user turns the sleeve in one direction on the chuck body to move the jaws together and grip a tool and in the opposite direction to move the jaws apart and release the tool.
Such a drill chuck is typically used in hand tools for drilling holes, driving screws, reaming, and the like. When used in a standard workshop some particles enter the chuck, which is designed as closed as possible to prevent this, but normally the minor amount of material than can enter the chuck is not a problem unless it builds up to the point of interfering with operation of the chuck mechanism.
When, however, such a chuck is used, for instance, in a bone drill for surgical/medical purposes, it is essential to be able to thoroughly clean and sterilize the chuck between uses, completely ridding of the tiniest particle. Thus it is necessary to be able to completely disassemble the chuck, clean and sterilize its parts, and reassemble it for each use. This is a time-consuming job that must normally be entrusted to a mechanically competent and trained person, greatly increasing the cost of using the equipment.